1. Field of the Invention
The present invention relates to ligation devices and methods, and more particularly to devices and methods for accurately locating and ligating an anatomical vessel.
2. Brief Description of the Related Art
The Doppler effect is currently utilized in many fields. For example, Doppler stethoscopes and Doppler wands are currently utilized to generate images of internal anatomical structures in patients, especially in mammalian patients. Continuous wave doppler sound signals are used to identify blood vessels, but do not provide feedback as to the distance of the vessel from the Doppler probe used. Pulsed wave Doppler has been used to identify blood vessels and, in conjunction with two dimensional (2D) imaging systems, identify the distance to a blood vessel and blood flow characteristics. Ultrasound systems with Doppler imaging are also currently used in medical fields, and typically produce gray-scale two-dimensional images. The addition of Doppler processing allows for the evaluation of fluid flow velocities through fluid conduits within the patient, and the relative position of these vessels to other anatomical structures.
Ligation devices have previously been proposed. These prior ligation devices have typically been used in laparascopic procedures, and have typically required that the anatomical feature of interest be dissected or visualized prior to ligation of that feature.
According to a first exemplary embodiment, a ligation device comprises a cannula having a proximal end, a distal end, and at least one lumen extending longitudinally from said proximal end to said distal end, a first extendable member slidably received in said cannula lumen, said first extendable member having a distal end and being movable in said lumen from a retracted position in which said first extendable member distal end is proximal said cannula distal end, and an extended position in which said first extendable member distal end is distal of said cannula distal end, said first extendable member including a detachable element at said first extendable member distal end, a second extendable member slidably received in said cannula lumen, said second extendable member having a distal end and being movable in said lumen from a retracted position in which said second extendable member distal end is proximal said cannula distal end, and an extended position in which said second extendable member distal end is distal of said cannula distal end, said second extendable member including a snare at said second extendable member distal end, and at least one of said first extendable member and said second extendable member including curved portions which extend laterally across said cannula when said at least one of said first extendable member and said second extendable member is in said extended position.
According to a second exemplary embodiment, a method of preparing an anatomical vessel for ligation comprises the steps of positioning a cannula adjacent to said vessel, said cannula including a first extendable member, a second extendable member, and a Doppler wand, and a distal end, transmitting ultrasound signals toward said vessel with said Doppler wand, receiving ultrasound signals reflected by said vessel with said Doppler wand, extending said first extendable member on a first side of said vessel, extending said second extendable member on a second side of said vessel opposite said first side, and extending a length of ligation material between said first and second extendable members on a side of said vessel opposite said cannula distal end.
According to a third exemplary embodiment, a device useful for guiding a length of ligation material around an anatomical feature comprises a cannula including a hollow interior, a distal end, and a fenestration in the cannula proximal of the distal end, a hollow arm positioned in the cannula at the fenestration, the hollow arm including a rotatable pivot by which the arm is mounted to the cannula, the arm being rotatable from a retracted orientation with the arm positioned inside the cannula and a deployed orientation with a portion of the arm rotated about the pivot and through the fenestration, at least one wire connected to the arm and extending proximally, and wherein when the at least one wire is pulled proximally, the arm is rotated about the pivot into the deployed orientation.